It is estimated that 1 in every 40 people of Ashkenazi Jewish ancestry carry a genetic change that gives them a higher lifetime risk for breast and ovarian cancer than the average person.
These genetic changes are known as "the founder mutations" because they can be traced back hundreds of years to common ancestors, or founders. These changes occur in the genes called BRCA1 and BRCA2 (named for BReast CAncer).
Ashkenazi Jews are 10 times more likely to carry a BRCA gene that increases their risk than the average person. (In the general population, 1 in 500 to 1 in 750 people carry a BRCA mutation.) Both men and women can carry these genes.
Today, Ashkenazi Jews live all over the world, but their ancestors most commonly came from Northern and Eastern Europe, including the countries of Poland, Russia, and Germany. The vast majority of Jews in the United States are of Ashkenazi origin. This is not true in other countries.
How High Is the Risk?
If you test positive for one of these gene changes, your risk to develop breast cancer is greater than average, and it increases as you get older.
The largest research study to date (2003) by Dr. Mary Claire King determined these risks to be:
| Age | Risk for Breast Cancer |
| 40 years | 20% |
| 60 years | 55% |
| 80 years | >80% |
| Gene Change | Lifetime Risk for Ovarian Cancer |
| BRCA1 | 54% |
| BRCA2 | 23% |
Your genetic status alone does not determine your entire risk for cancer. Other factors such as environmental exposures, lifestyle, hormonal factors, age at first menstruation, and age at first childbirth all play a role, but no role is more significant than gene status.
What Can You Do About Risk?
If you are at risk for hereditary breast and ovarian cancer, there are lifestyle measures and preventive treatment options that you can take to reduce your risk. Which steps are appropriate for you depends on your individual situation.
Scientific Literature References
